1. Field of the Invention
The present invention relates to handheld tools that can be used to condition and sharpen the cutting edge of a cabinet scraper blade or like tool blade. More particularly, the present invention relates to a tool that embodies a file and a sharpening stone for conditioning the edge of a blade and a consolidating pin and burnishing rod for creating a desired hooked configuration to the edge of the blade.
2. Prior Art Statement
Tools such as cabinet scrapers, hide scrapers and the like use planar blades wherein the sharpened edge of the blade is slightly hooked so as to cut into the material over which the tool is drawn. Forming the proper hook onto the sharpened edge of such a tool is traditionally a difficult and time consuming task that takes a great degree of skill. The task is complicated by the fact that the degree of the hook is changed depending upon the task being preformed with the tool. For instance, with cabinet scrapers, a large hook would be used for paint or varnish stripping, while a much smaller hook would be used for marquetry or cleaning raised grain for finishing.
Traditionally, the conditioning and sharpening of a scraper tool blade is a four step process that requires four separate tools. The first step in conditioning a scraper blade is to square the blade edge by passing the cutting edge of the blade over a fine tooth file. This step is traditionally called jointing and is performed until the scraper edge is flat with no discernable nicks or shear marks. Next, the edge of the scraper blade is passed over a sharpening stone which removes any roughness from the edge left by the file during jointing. In both the jointing step and the sharpening stone step, it is very important that the plane of the scraper is perpendicular to the plane of the file or sharpening stone. As such, great care is taken in mounting the file, stone or blade in a jig or vice to ensure the proper orientational configurations. This adds greatly to the time it takes to condition such a blade.
After the cutting edge of a scraper blade is conditioned on the sharpening stone, a consolidating pin is passed over the now flat edge of the blade. This causes the edge of the blade to become work hardened to a predetermined degree depending upon both how firmly the blade is biased against the consolidating pin, and how many times the conditioning pin is passed over the blade. Once the edge is work hardened to a desired degree, a burnishing rod is stroked along the hardened edge of the blade at an angle between 0.degree. and 25.degree.. The burnishing rod hones an edge, thereby creating the desired hook-shaped configuration. The degree in size of the hook is dependent upon the angle of the burnishing rod in forming the hook.
In the prior art there are many devices that assist a person in forming the desired hooked edge on a scraper blade. Such prior art is exemplified by U.S. Pat. No. 102,994 to Webster, entitled SHARPENING MACHINE and U.S. Pat. No. 5,099,722 to LEE, entitled CABINET SCRAPER BURNISHING TOOL. In both references a tool is shown that helps perform the burnishing step of the before described traditional blade conditioning technique. However, these prior art tools require that a scraper blade first be jointed, stone stroked and conditioning pin stroked before these tools can be used to burnish an edge. Consequently, the quality of the burnished edge is high but there is little reduction in the time and labor needed to obtain such a burnished edge.
Accordingly, a need exists in the art for a single tool that can perform all of the steps required in conditioning and sharpening a scraper blade. Such a tool will eliminate the cost of multiple tools and the skills need to handle those tools, thereby producing considerable cost and labor savings.